Spark plug



Patented Apr. 8, 1924.

UNITED STATES JOHN' J'. DANIELE, OF DULUTH, MINNESOTA..

sranx PLUG.

Applcation led January 20, 1921. Serial No. 438,583.

To all whom. it may concern:

Be it known that l'. .ToiiN J. DANIE'LS, a citizen of the United States. residing at Duluth. in the county of St. Louis and Sta-te I of Minnesota, have invented certain new and useful Improvements in Spark Plugs` of which the following is a specification, reference being had therein to the accompanying drawing.

This invention relates to spark plugs for internal combustion engines and consists not only in an improved form of plug but also in a novel method for maintaining the cooperative parts of the plug in leak proof 1I condition. The principal object is to provide such a plug that will be as near leak proof as possible.

Another object is to produce a plug whichr is exceptionally easy, of access for cleaning i purposes and stilly another object is to provide a novel means for simultaneously cleaning the plug and insuring it against leakage.

Still other objects and advantages of the il peculiar construction will appear in the further description of the invention.

Referring to the accompanying drawing in which like reference characters indicate like parts;

Fig. 1 is a central vertical sectional view throughl one ofmy vcompletely assembled lu p 2 is a similar view through the body portion of the plug showing the cleaning and packing implement in position therein in elevation H Fig. 3 is a vertical central sectional view through the centermost plug engaging portion of the combination cleaner and wrench; 0 Fig` 4 is a top plan View of the conically shaped compressor portion of the cleaner and packer;

Fig. 5 is a side elevation of the powde container o-r can; and

Fig. 6 is a plan view of two of the plugs illustrating the automatically operated means for maintaining a tight union of the separable parts of the plug.

1 represents the main body portion of the plug, having the axial bore 2 through the lower portion thereof which terminates at its uppermost end in a conically shaped ybore into which the enlarged tapered portion 3 of the axially disposed porcelain u fits, the lower portion 4 of the porcelain being further reduced in size and tapered towards its lower end, and the uppermost portion 5 being cylindrical and of somewhat smaller diameter than the uppermost end of the tapered portion 3. i

In the'inner wall of the conical portion of the bore in the plug are formed a plurality of recesses indicated at 6, 7 and 8, the lower most one, 6, being preferably the largest and deepest. About the tapered portion 3 of the porcelain is formed a circumferentially disposed annular recess 9 into which is tted a flat rubber ring gasket 10.

The lower outer portion 11 of the body 1 of the plug is externally screw threaded for application tothe ordinary screw threaded hole in the engine as is common to u such plugs, while the upper portion 12 of the body 1 of the plug is externally screw threaded and receives the compression cap 13 which is internally screw threaded for such purpose and forcibly holds the porcelain within the body 1 by impinging the upper edge of the annular ring 14 which rests upon the shoulder 15 formed at the juncture of the beveled portion 3 and the cylindrical portion 5 of the porcelain. The upwardly extending cylindrical portion of the cap 13 is cut away on opposite sides as at 16 for the reception of a wrench; a particularly suitable one of which is illustrated at 17 and is a portion of the cleaning and packing mechanism. A central circular projection 18 is formed integral with the cap 13 and is provided with a plurality of holes 19 spaced circumferentially thereabouts. Two opposite sides of the upper end of the cylindrical portion 5 of the porcelain are cut away at an angle as indicated at 'Q0 and upon which end of the porcelain is fitted the metallic cap 21 having an upwardly extending reduced cylindrical portion 22 which is externallythreaded for the reception of a suitable nut 23 for holding the wire connection thereupon as is common.

The cap 21 is cut away upon its under face to, fift the cut away portion 20 of the upper end of the porcelain so that when the former is placed tightly upon the latter one cannot be turned without the other. Axially through fthe porcelain extends the usual terminal 24 which is screw threaded at its upper end for engagement within the bore of the cap'21.' The terminal'24 has a nut 25 fixed adjacent its lower bent end so that it may be tightly held within the porcelain by its being screwed into the Acap from the lower end thereof. and the bent end 26 of the terminal is turned to face the inner edge of the bore 2 of the spark plug forming a gap between the edge of the bore and the end of the terminal in which gap the spark occurs as is common to similar devices. At 27 I have shown a rubber washer about the terminal 24 and against which the cap 21 impinges to form a leak roof joint.

On rst consideration it may be considered impractical to place a rubber gasket in or about a spark plug, but my experience has been that such is perfectly practical and the same is considered a novel part of A this invention.

The recesses 6. 7 and 8 are to be filled with a packing powder to prevent leakage intermediate of the porcelain and the metal body portion l of the plug and for this purposeI have discovered that finely powdered soap stone is particularly well adapted. In Figures 2, 3 and 4, I have illustrated a combination packing and cleaning device for the application of powder to the recesses 6, 7 and 8, and the cleaning of the bore 2 of the plug, which is accomplished in the followinni manner. y

Vhen the parts of the plug are separated, the cleaner is inserted within the body portion l from the upper end thereof until the compression cone 28 snugly rests within the conical portion of the bore of the plug, as shown in Figure 2, and during which insertion t-he prongs29 of the cleaner, (as it is bifurcated substantially the full length thereof), are sprung together slightly, they being normally wider apart than the diameter of the bore 2. This will bring the outer edges of the prongs bearing tightly against the walls of the bore but not sufficiently so to prevent the ready rotation of the cleaner within the plug for both cleaning the walls of the bore and forcing the powder into the channels or recesses 6, 7 and 8, as the packing cone 28 has an arcuately cut away section indicated at 30 into which powder is intermittently squirted by the use of the conveniently shaped can 31, it being understood that the cone 28 with the cleaner is rotated in a clockwise or righthand direction during such process and the cut away portion 30 is so shaped as to naturally lit the powder radially into the grooves. During the continuation of this process the grooves 6, 7 and 8 will be thoroughly packed with the soap stone powder, and. in fact. a thin film of the powder becomes impact upon the entire wall of the conically shaped portion of the bore in the plug, and, at the same time, the parallel y portion 2 of the bore will become thoroughly cleansed of any collection of carbon that might have existed. Then the cleaner and packer is removed and the porcelain placed in position and there securely held by the screwing down of the cap 13.

The prongs or tangs 29 of the combination cleaner. wrench aud packer are notched as at 32 for the reception of the packing cone 28 which is forcibly slid over the free ends of the tangs to its position as illustrated in Figure 3, it having a rectangularly shaped slot 33 therein for such purpose and may be easily removed from the taugs when desired for repair or renewal.

Now, in the event of the porcelain becoming at all loosened within the plug, I have illustra-ted, as attached intermediate of two of the caps 13, a. contractile spiral spring 34, which is provided with hooked ends, for engagement with any of the holes 19 within said cap, and, as illustrated in Figure 6 of the drawing, when such spring is expanded and hooked within one hole of one cap aud the opposite hole of the other cap, the spring will exert a continual clockwise stress upon the two caps which will tend to keep them tightly screwed down at all times.

As before stated I have made quite extensive experiments with a number of spark plugs made in exact accordance with the illustration here given and have found them to work very satisfactorily and in respect to the rubber gaskets above referred to, answer every purpose desired of them. It may be that the presence of compact films of such stone powder may have something to do with keeping the porcelain portion of the plug cool, at any rate, the plugs have proven a success and it is the inventors be lief that their use will prove a marked step in advance in the art.

Having thus described my invention what I claim and desire to secure by Letters Patent, is:

l. A spark plug of the character described comprising in combination a metal body portion externally screw threaded upon its lower end and screw threaded upon its upper end. a screw threaded porcelain holding compression cap for application to the upper end of the body portion, a porcelain terminal carrying core within the body portion and extending through the compression cap, the central portion of said core being conically shaped and provided with an annular shoulder. means for the reception of powdered packing material intermediate of the porcelain core and the body portion, powdered packing material within said means, a rubber gasket adjacent the shoulder on the core to prevent the escape of the packing material, and means whereby the compression cap may be made to securely hold the porcelain and body portion united with the packing material forming a tight applied to an internal combustion engine, joint therebetween, substantially as deof holding means diagonally disposed acro ll scribed. the space intermediate of the spark plugs 2. The combination with two spaced and attached to the compression caps there- 5 spark plugs having compression caps and of at diametrically opposite sides for the applied to an internal combustion engine, purpose of preventing the caps moving any of resilient means diagonally disposed across considerable distance independently. 20 the space intermediate of the spark plugs and In testimony whereof I hereunto aflix my att-ached to the compression caps thereof at signature in the presence of two witnesses.

l diametrically opposite sides, for the pury JOHN J. DANIELS.

pose described. Witnesses:

3. The combination with two spaced S. C. BnoNsoN,

spark plugs having compression caps and S. Gmo. S'rnvnNs. 

